Most of us feel it: that lift in spirit you feel when you dig in the garden, set foot on the beach or walk into the woods. As the world becomes more urbanized, fewer of us have those experiences on a regular basis. If you want to experience nature, you have to seek it out.

Richard Louv, journalist, author and co-founder and of the Children & Nature Network is helping galvanize an international movement to connect people and communities to the natural world.

In his book, Last Child in the Woods: Saving Our Children from Nature-Deficit Disorder was focused on how to reconnect children with nature. In The Nature Principle, he calls to action the rest of us. He argues that connecting with and being a part of nature will not just improve creativity and mental sharpness, physical health and wellness; but also build smarter and more sustainable businesses, communities, and economies.

A growing body of research has shown quantifiable evidence that being in nature is good for your mental health. In a recent Stanford-led study, published in the Proceedings of the National Academy of Science, they looked at the effects of urbanization on mental health. Decreased nature experience has been thought to be the link between urbanization and mental illness, but which mechanism is the link between nature experience and mental illness? They theorized that it has to do with rumination, which is defined as a “– repetitive thought focused on negative emotions” and is associated with heightened risk for depression and other mental illnesses.

In the study, two groups of participants walked for 90 minutes, one in a grassland area scattered with oak trees and shrubs, the other along a traffic-heavy four-lane roadway. Before and after, the researchers measured heart and respiration rates, performed brain scans and had participants fill out questionnaires. The results of the study demonstrate that 90-min walks in natural settings decrease both self-reported rumination and neural activity in the subgenual prefrontal cortex (sgPFC), whereas a 90-min walk in an urban setting has no such effects on self-reported rumination or neural activity. In other studies, the sgPFC has been associated with a self-focused behavioral withdrawal linked to rumination in both depressed and healthy individuals.

This study suggests that having easily accessible natural areas within urban environments is a potentially critical resource, just as Louv and many of his colleagues have been arguing. Bringing nature into our classrooms, our cities and our living spaces can have a broad and significant positive impact.